source/glsl/parser.cpp

   1 #include <msp/core/raii.h>
   2 #include <msp/strings/format.h>
   3 #include <msp/strings/regex.h>
   4 #include <msp/strings/utils.h>
   5 #include "builtin.h"
   6 #include "glsl_error.h"
   7 #include "parser.h"
   8
   9 #undef interface
  10
  11 using namespace std;
  12
  13 namespace Msp {
  14 namespace GL {
  15 namespace SL {
  16
  17 Parser::Parser():
  18         preprocessor(tokenizer),
  19         module(0)
  20 {
  21         tokenizer.signal_preprocess.connect(sigc::mem_fun(&preprocessor, &Preprocessor::preprocess));
  22         preprocessor.signal_version.connect(sigc::mem_fun(this, &Parser::set_required_version));
  23         preprocessor.signal_source.connect(sigc::mem_fun(this, &Parser::source_reference));
  24         preprocessor.signal_stage_change.connect(sigc::mem_fun(this, &Parser::stage_change));
  25         preprocessor.signal_line.connect(sigc::mem_fun(this, &Parser::line_change));
  26 }
  27
  28 Parser::~Parser()
  29 {
  30         delete module;
  31 }
  32
  33 Module &Parser::parse(const string &s, const string &n, int i)
  34 {
  35         source = s;
  36         parse_source(n, i);
  37         return *module;
  38 }
  39
  40 Module &Parser::parse(IO::Base &io, const string &n, int i)
  41 {
  42         source = string();
  43         while(!io.eof())
  44         {
  45                 char buffer[4096];
  46                 unsigned len = io.read(buffer, sizeof(buffer));
  47                 source.append(buffer, len);
  48         }
  49         parse_source(n, i);
  50         return *module;
  51 }
  52
  53 void Parser::parse_source(const string &name, int index)
  54 {
  55         delete module;
  56         module = new Module;
  57
  58         cur_stage = &module->shared;
  59         base_index = index;
  60         source_index = index;
  61         if(index>=0)
  62                 source_reference(1, name);
  63
  64         // TODO Need to somehow get type names from imports
  65         if(const Stage *builtin = get_builtins(Stage::SHARED))
  66         {
  67                 for(map<string, TypeDeclaration *>::const_iterator i=builtin->types.begin(); i!=builtin->types.end(); ++i)
  68                         declared_types.insert(i->first);
  69         }
  70         else
  71         {
  72                 declared_types.insert("void");
  73                 declared_types.insert("bool");
  74                 declared_types.insert("int");
  75                 declared_types.insert("float");
  76         }
  77
  78         tokenizer.begin(source, name);
  79         allow_stage_change = true;
  80         while(!tokenizer.peek_token().empty())
  81                 if(RefPtr<Statement> statement = parse_with_recovery(&Parser::parse_global_declaration))
  82                         cur_stage->content.body.push_back(statement);
  83
  84         if(!errors.empty())
  85                 throw invalid_shader_source(join(errors.begin(), errors.end(), "\n"));
  86 }
  87
  88 void Parser::set_required_version(const Version &ver)
  89 {
  90         cur_stage->required_features.glsl_version = ver;
  91 }
  92
  93 void Parser::source_reference(unsigned index, const string &name)
  94 {
  95         if(index<1 || base_index<0)
  96                 throw invalid_shader_source(tokenizer.get_location(), "Invalid source reference");
  97
  98         module->source_map.set_name(base_index+index-1, name);
  99 }
 100
 101 void Parser::stage_change(Stage::Type stage)
 102 {
 103         if(!allow_stage_change)
 104                 throw invalid_shader_source(tokenizer.get_location(), "Changing stage not allowed here");
 105         else if(stage<=cur_stage->type)
 106                 throw invalid_shader_source(tokenizer.get_location(), "Stage '%s' not allowed here", Stage::get_stage_name(stage));
 107
 108         module->stages.push_back(stage);
 109
 110         if(cur_stage->type!=Stage::SHARED)
 111                 module->stages.back().previous = cur_stage;
 112         cur_stage = &module->stages.back();
 113 }
 114
 115 void Parser::line_change(int index, unsigned line)
 116 {
 117         if(index>0)
 118                 source_index = base_index+index-1;
 119         else if(index==0)
 120                 source_index = 0;
 121         else
 122                 index = source_index;
 123
 124         string name = module->source_map.get_name(index);
 125         if(name.empty())
 126                 name = format("<%d>", index);
 127         tokenizer.set_location(Location(name, line));
 128 }
 129
 130 string Parser::expect_type()
 131 {
 132         string token = tokenizer.parse_token();
 133         if(!is_type(token))
 134                 throw parse_error(tokenizer.get_location(), token, "a type");
 135         return token;
 136 }
 137
 138 string Parser::expect_identifier()
 139 {
 140         string token = tokenizer.parse_token();
 141         if(!is_identifier(token))
 142                 throw parse_error(tokenizer.get_location(), token, "an identifier");
 143         return token;
 144 }
 145
 146 int Parser::expect_integer()
 147 {
 148         string token = tokenizer.parse_token();
 149         if(!isnumrc(token))
 150                 throw parse_error(tokenizer.get_location(), token, "an integer literal");
 151         return lexical_cast<int>(token);
 152 }
 153
 154 bool Parser::check(const string &token)
 155 {
 156         bool result = (tokenizer.peek_token()==token);
 157         if(result)
 158                 tokenizer.parse_token();
 159         return result;
 160 }
 161
 162 bool Parser::is_interface_qualifier(const string &token)
 163 {
 164         return (token=="uniform" || token=="in" || token=="out");
 165 }
 166
 167 bool Parser::is_sampling_qualifier(const string &token)
 168 {
 169         return (token=="centroid" || token=="sample");
 170 }
 171
 172 bool Parser::is_interpolation_qualifier(const string &token)
 173 {
 174         return (token=="smooth" || token=="flat" || token=="noperspective");
 175 }
 176
 177 bool Parser::is_precision_qualifier(const string &token)
 178 {
 179         return (token=="highp" || token=="mediump" || token=="lowp");
 180 }
 181
 182 bool Parser::is_qualifier(const string &token)
 183 {
 184         return (token=="const" ||
 185                 is_interface_qualifier(token) ||
 186                 is_sampling_qualifier(token) ||
 187                 is_interpolation_qualifier(token) ||
 188                 is_precision_qualifier(token));
 189 }
 190
 191 bool Parser::is_type(const string &token)
 192 {
 193         return declared_types.count(token);
 194 }
 195
 196 bool Parser::is_identifier(const string &token)
 197 {
 198         static Regex re("^[a-zA-Z_][a-zA-Z0-9_]*$");
 199         return re.match(token);
 200 }
 201
 202 template<typename T>
 203 RefPtr<T> Parser::create_node()
 204 {
 205         RefPtr<T> node = new T;
 206         node->source = source_index;
 207         node->line = tokenizer.get_location().line;
 208         return node;
 209 }
 210
 211 template<typename T>
 212 RefPtr<T> Parser::parse_with_recovery(RefPtr<T> (Parser::*parse_func)())
 213 {
 214         tokenizer.clear_progress_mark();
 215         try
 216         {
 217                 return (this->*parse_func)();
 218         }
 219         catch(const invalid_shader_source &exc)
 220         {
 221                 errors.push_back(exc.what());
 222         }
 223
 224         if(tokenizer.get_last_token()!=";" || !tokenizer.get_progress_mark())
 225         {
 226                 unsigned scope_level = 0;
 227                 while(1)
 228                 {
 229                         if(tokenizer.peek_token()=="}" && scope_level==0)
 230                         {
 231                                 if(!tokenizer.get_progress_mark())
 232                                         tokenizer.parse_token();
 233                                 break;
 234                         }
 235
 236                         string token = tokenizer.parse_token();
 237                         if(token=="}")
 238                         {
 239                                 --scope_level;
 240                                 if(scope_level==0)
 241                                         break;
 242                         }
 243                         else if(token=="{")
 244                                 ++scope_level;
 245                         else if(token==";" && scope_level==0)
 246                                 break;
 247                         else if(token.empty())
 248                                 break;
 249                 }
 250         }
 251
 252         return RefPtr<T>();
 253 }
 254
 255 RefPtr<Statement> Parser::parse_global_declaration()
 256 {
 257         string token = tokenizer.peek_token();
 258         SetFlag disallow(allow_stage_change, false);
 259
 260         if(token=="import")
 261                 return parse_import();
 262         else if(token=="precision")
 263                 return parse_precision();
 264         else if(token=="layout")
 265         {
 266                 RefPtr<Layout> layout = parse_layout();
 267                 token = tokenizer.peek_token();
 268                 if(is_interface_qualifier(token) && tokenizer.peek_token(1)==";")
 269                 {
 270                         RefPtr<InterfaceLayout> iface_lo = create_node<InterfaceLayout>();
 271                         iface_lo->layout.qualifiers = layout->qualifiers;
 272                         iface_lo->interface = tokenizer.parse_token();
 273                         tokenizer.expect(";");
 274                         return iface_lo;
 275                 }
 276                 else if(is_interface_qualifier(token) && tokenizer.peek_token(2)=="{")
 277                 {
 278                         RefPtr<InterfaceBlock> iface = parse_interface_block();
 279                         iface->layout = layout;
 280                         return iface;
 281                 }
 282                 else
 283                 {
 284                         RefPtr<VariableDeclaration> var = parse_variable_declaration();
 285                         var->layout = layout;
 286                         return var;
 287                 }
 288         }
 289         else if(token=="typedef")
 290                 return parse_type_declaration();
 291         else if(token=="struct")
 292                 return parse_struct_declaration();
 293         else if(is_interface_qualifier(token))
 294         {
 295                 string next = tokenizer.peek_token(1);
 296                 if(is_type(next) || is_qualifier(next))
 297                         return parse_variable_declaration();
 298                 else
 299                         return parse_interface_block();
 300         }
 301         else if(is_qualifier(token))
 302                 return parse_variable_declaration();
 303         else if(token=="virtual")
 304                 return parse_function_declaration();
 305         else if(is_type(token))
 306         {
 307                 if(tokenizer.peek_token(2)=="(")
 308                         return parse_function_declaration();
 309                 else
 310                         return parse_variable_declaration();
 311         }
 312         else if(token.empty())
 313                 return 0;
 314         else
 315                 throw parse_error(tokenizer.get_location(), token, "a global declaration");
 316 }
 317
 318 RefPtr<Statement> Parser::parse_statement()
 319 {
 320         string token = tokenizer.peek_token();
 321         if(token=="if")
 322                 return parse_conditional();
 323         else if(token=="for")
 324                 return parse_for();
 325         else if(token=="while")
 326                 return parse_while();
 327         else if(token=="passthrough")
 328                 return parse_passthrough();
 329         else if(token=="return")
 330                 return parse_return();
 331         else if(token=="break" || token=="continue" || token=="discard")
 332         {
 333                 RefPtr<Jump> jump = create_node<Jump>();
 334                 jump->keyword = tokenizer.parse_token();
 335                 tokenizer.expect(";");
 336
 337                 return jump;
 338         }
 339         else if(is_qualifier(token) || is_type(token))
 340                 return parse_variable_declaration();
 341         else if(token==";")
 342         {
 343                 tokenizer.parse_token();
 344                 throw invalid_shader_source(tokenizer.get_location(), "Empty statement not allowed");
 345         }
 346         else if(!token.empty())
 347         {
 348                 RefPtr<ExpressionStatement> expr = create_node<ExpressionStatement>();
 349                 expr->expression = parse_expression();
 350                 tokenizer.expect(";");
 351
 352                 return expr;
 353         }
 354         else
 355                 throw parse_error(tokenizer.get_location(), token, "a statement");
 356 }
 357
 358 RefPtr<Import> Parser::parse_import()
 359 {
 360         if(cur_stage->type!=Stage::SHARED)
 361                 throw invalid_shader_source(tokenizer.get_location(), "Imports are only allowed in the shared section");
 362
 363         tokenizer.expect("import");
 364         RefPtr<Import> import = create_node<Import>();
 365         import->module = expect_identifier();
 366         tokenizer.expect(";");
 367         return import;
 368 }
 369
 370 RefPtr<Precision> Parser::parse_precision()
 371 {
 372         tokenizer.expect("precision");
 373         RefPtr<Precision> precision = create_node<Precision>();
 374
 375         precision->precision = tokenizer.parse_token();
 376         if(!is_precision_qualifier(precision->precision))
 377                 throw parse_error(tokenizer.get_location(), precision->precision, "a precision qualifier");
 378
 379         // TODO Add validation for this
 380         precision->type = expect_type();
 381
 382         tokenizer.expect(";");
 383
 384         return precision;
 385 }
 386
 387 RefPtr<Layout> Parser::parse_layout()
 388 {
 389         tokenizer.expect("layout");
 390         tokenizer.expect("(");
 391         RefPtr<Layout> layout = create_node<Layout>();
 392         while(1)
 393         {
 394                 string token = tokenizer.parse_token();
 395                 if(token==")")
 396                         throw parse_error(tokenizer.get_location(), token, "a layout qualifier name");
 397
 398                 layout->qualifiers.push_back(Layout::Qualifier());
 399                 Layout::Qualifier &qual = layout->qualifiers.back();
 400                 qual.name = token;
 401
 402                 if((qual.has_value = check("=")))
 403                 {
 404                         if(qual.name=="constant_id" && tokenizer.peek_token()=="auto")
 405                         {
 406                                 qual.value = -1;
 407                                 tokenizer.parse_token();
 408                         }
 409                         else
 410                                 qual.value = expect_integer();
 411                 }
 412
 413                 if(tokenizer.peek_token()==")")
 414                         break;
 415
 416                 tokenizer.expect(",");
 417         }
 418         tokenizer.expect(")");
 419
 420         return layout;
 421 }
 422
 423 template<typename T>
 424 void Parser::parse_block(Block &block, bool require_braces, RefPtr<T> (Parser::*parse_content)())
 425 {
 426         bool have_braces = (require_braces || tokenizer.peek_token()=="{");
 427         if(have_braces)
 428                 tokenizer.expect("{");
 429
 430         if(have_braces)
 431         {
 432                 while(tokenizer.peek_token()!="}")
 433                         if(RefPtr<Statement> node = parse_with_recovery(parse_content))
 434                                 block.body.push_back(node);
 435         }
 436         else
 437                 block.body.push_back((this->*parse_content)());
 438
 439         block.use_braces = (require_braces || block.body.size()!=1);
 440
 441         if(have_braces)
 442                 tokenizer.expect("}");
 443 }
 444
 445 RefPtr<Expression> Parser::parse_expression(const Operator *outer_oper)
 446 {
 447         unsigned outer_precedence = (outer_oper ? outer_oper->precedence+(outer_oper->assoc==Operator::RIGHT_TO_LEFT) : 20);
 448         RefPtr<Expression> left;
 449         VariableReference *left_var = 0;
 450         while(1)
 451         {
 452                 string token = tokenizer.peek_token();
 453
 454                 const Operator *oper = 0;
 455                 for(const Operator *i=Operator::operators; (!oper && i->type); ++i)
 456                         if(token==i->token && (!left || i->type!=Operator::PREFIX) && (left || i->type!=Operator::POSTFIX))
 457                                 oper = i;
 458
 459                 bool lower_precedence = (oper && oper->type!=Operator::PREFIX && oper->precedence>=outer_precedence);
 460                 if(token==";" || token==")" || token=="]" || token=="," || token==":" || lower_precedence)
 461                 {
 462                         if(left)
 463                                 return left;
 464                         else
 465                                 throw parse_error(tokenizer.get_location(), token, "an expression");
 466                 }
 467                 else if(left)
 468                 {
 469                         if(token=="(")
 470                         {
 471                                 if(!left_var)
 472                                         throw invalid_shader_source(tokenizer.get_location(), "Syntax error before '(': function name must be an identifier");
 473                                 left = parse_function_call(*left_var);
 474                         }
 475                         else if(token==".")
 476                         {
 477                                 RefPtr<MemberAccess> memacc = create_node<MemberAccess>();
 478                                 memacc->left = left;
 479                                 memacc->oper = oper;
 480                                 tokenizer.parse_token();
 481                                 memacc->member = expect_identifier();
 482                                 left = memacc;
 483                         }
 484                         else if(oper && oper->type==Operator::POSTFIX)
 485                         {
 486                                 RefPtr<UnaryExpression> unary = create_node<UnaryExpression>();
 487                                 unary->oper = oper;
 488                                 tokenizer.parse_token();
 489                                 unary->expression = left;
 490                                 left = unary;
 491                         }
 492                         else if(oper && oper->type==Operator::BINARY)
 493                                 left = parse_binary(left, *oper);
 494                         else if(oper && oper->type==Operator::TERNARY)
 495                                 left = parse_ternary(left, *oper);
 496                         else
 497                                 throw parse_error(tokenizer.get_location(), token, "an operator");
 498                         left_var = 0;
 499                 }
 500                 else
 501                 {
 502                         if(token=="(")
 503                         {
 504                                 tokenizer.parse_token();
 505                                 left = parse_expression();
 506                                 tokenizer.expect(")");
 507                         }
 508                         else if(isdigit(token[0]) || token=="true" || token=="false")
 509                                 left = parse_literal();
 510                         else if(is_identifier(token))
 511                         {
 512                                 RefPtr<VariableReference> var = create_node<VariableReference>();
 513                                 var->name = expect_identifier();
 514                                 left = var;
 515                                 left_var = var.get();
 516                         }
 517                         else if(oper && oper->type==Operator::PREFIX)
 518                         {
 519                                 RefPtr<UnaryExpression> unary = create_node<UnaryExpression>();
 520                                 unary->oper = oper;
 521                                 tokenizer.parse_token();
 522                                 unary->expression = parse_expression(oper);
 523                                 left = unary;
 524                         }
 525                         else
 526                                 throw parse_error(tokenizer.get_location(), token, "an expression");
 527                 }
 528         }
 529 }
 530
 531 RefPtr<Literal> Parser::parse_literal()
 532 {
 533         RefPtr<Literal> literal = create_node<Literal>();
 534         literal->token = tokenizer.parse_token();
 535         if(isdigit(literal->token[0]))
 536         {
 537                 // TODO have the tokenizer return the type of the token
 538                 if(isnumrc(literal->token))
 539                         literal->value = lexical_cast<int>(literal->token);
 540                 else
 541                         literal->value = lexical_cast<float>(literal->token);
 542         }
 543         else if(literal->token=="true" || literal->token=="false")
 544                 literal->value = (literal->token=="true");
 545         else
 546                 throw parse_error(tokenizer.get_location(), literal->token, "a literal");
 547
 548         return literal;
 549 }
 550
 551 RefPtr<BinaryExpression> Parser::parse_binary(const RefPtr<Expression> &left, const Operator &oper)
 552 {
 553         RefPtr<BinaryExpression> binary = (oper.precedence==16 ?
 554                 static_cast<RefPtr<BinaryExpression> >(create_node<Assignment>()) : create_node<BinaryExpression>());
 555         binary->left = left;
 556         binary->oper = &oper;
 557         tokenizer.expect(oper.token);
 558         if(oper.token2[0])
 559         {
 560                 binary->right = parse_expression();
 561                 tokenizer.expect(oper.token2);
 562         }
 563         else
 564                 binary->right = parse_expression(&oper);
 565         return binary;
 566 }
 567
 568 RefPtr<TernaryExpression> Parser::parse_ternary(const RefPtr<Expression> &cond, const Operator &oper)
 569 {
 570         RefPtr<TernaryExpression> ternary = create_node<TernaryExpression>();
 571         ternary->condition = cond;
 572         ternary->oper = &oper;
 573         tokenizer.expect("?");
 574         ternary->true_expr = parse_expression(&oper);
 575         tokenizer.expect(":");
 576         ternary->false_expr = parse_expression(&oper);
 577         return ternary;
 578 }
 579
 580 RefPtr<FunctionCall> Parser::parse_function_call(const VariableReference &var)
 581 {
 582         RefPtr<FunctionCall> call = create_node<FunctionCall>();
 583         call->name = var.name;
 584         call->oper = &Operator::get_operator("(", Operator::POSTFIX);
 585         tokenizer.expect("(");
 586         while(tokenizer.peek_token()!=")")
 587         {
 588                 if(!call->arguments.empty())
 589                         tokenizer.expect(",");
 590                 call->arguments.push_back(parse_expression());
 591         }
 592         tokenizer.expect(")");
 593         return call;
 594 }
 595
 596 RefPtr<TypeDeclaration> Parser::parse_type_declaration()
 597 {
 598         tokenizer.expect("typedef");
 599
 600         RefPtr<TypeDeclaration> type;
 601         if(tokenizer.peek_token()=="image")
 602                 type = parse_image_type_declaration();
 603         else
 604                 type = parse_basic_type_declaration();
 605
 606         tokenizer.expect(";");
 607         declared_types.insert(type->name);
 608         return type;
 609 }
 610
 611 RefPtr<BasicTypeDeclaration> Parser::parse_basic_type_declaration()
 612 {
 613         RefPtr<BasicTypeDeclaration> type = create_node<BasicTypeDeclaration>();
 614
 615         if(tokenizer.peek_token()=="vector")
 616         {
 617                 type->kind = BasicTypeDeclaration::VECTOR;
 618
 619                 tokenizer.parse_token();
 620                 tokenizer.expect("(");
 621                 type->size = expect_integer();
 622                 tokenizer.expect(")");
 623         }
 624
 625         type->base = expect_type();
 626         type->name = expect_identifier();
 627
 628         if(type->kind==BasicTypeDeclaration::ALIAS && check("["))
 629         {
 630                 type->kind = BasicTypeDeclaration::ARRAY;
 631                 tokenizer.expect("]");
 632         }
 633
 634         return type;
 635 }
 636
 637 RefPtr<ImageTypeDeclaration> Parser::parse_image_type_declaration()
 638 {
 639         tokenizer.expect("image");
 640         tokenizer.expect("(");
 641
 642         RefPtr<ImageTypeDeclaration> type = create_node<ImageTypeDeclaration>();
 643         while(1)
 644         {
 645                 string token = tokenizer.parse_token();
 646                 if(token=="dimensions")
 647                 {
 648                         tokenizer.expect("=");
 649                         token = tokenizer.parse_token();
 650                         if(token=="1")
 651                                 type->dimensions = ImageTypeDeclaration::ONE;
 652                         else if(token=="2")
 653                                 type->dimensions = ImageTypeDeclaration::TWO;
 654                         else if(token=="3")
 655                                 type->dimensions = ImageTypeDeclaration::THREE;
 656                         else if(token=="cube")
 657                                 type->dimensions = ImageTypeDeclaration::CUBE;
 658                         else
 659                                 throw parse_error(tokenizer.get_location(), token, "dimensions");
 660
 661                         if(check("["))
 662                         {
 663                                 type->array = true;
 664                                 tokenizer.expect("]");
 665                         }
 666                 }
 667                 else if(token=="sampled")
 668                         type->sampled = true;
 669                 else if(token=="shadow")
 670                         type->shadow = true;
 671                 else
 672                         throw parse_error(tokenizer.get_location(), token, "image type attribute");
 673
 674                 token = tokenizer.peek_token();
 675                 if(token==")")
 676                         break;
 677
 678                 tokenizer.expect(",");
 679         }
 680         tokenizer.expect(")");
 681
 682         type->base = expect_type();
 683         type->name = expect_identifier();
 684
 685         return type;
 686 }
 687
 688 RefPtr<StructDeclaration> Parser::parse_struct_declaration()
 689 {
 690         tokenizer.expect("struct");
 691         RefPtr<StructDeclaration> strct = create_node<StructDeclaration>();
 692
 693         strct->name = expect_identifier();
 694         parse_block(strct->members, true, &Parser::parse_variable_declaration);
 695         tokenizer.expect(";");
 696
 697         declared_types.insert(strct->name);
 698         return strct;
 699 }
 700
 701 RefPtr<VariableDeclaration> Parser::parse_variable_declaration()
 702 {
 703         RefPtr<VariableDeclaration> var = create_node<VariableDeclaration>();
 704
 705         string token = tokenizer.peek_token();
 706         while(is_qualifier(token))
 707         {
 708                 tokenizer.parse_token();
 709                 if(is_interface_qualifier(token))
 710                         var->interface = token;
 711                 else if(is_sampling_qualifier(token))
 712                         var->sampling = token;
 713                 else if(is_interpolation_qualifier(token))
 714                         var->interpolation = token;
 715                 else if(is_precision_qualifier(token))
 716                         var->precision = token;
 717                 else if(token=="const")
 718                         var->constant = true;
 719                 token = tokenizer.peek_token();
 720         }
 721
 722         var->type = expect_type();
 723         var->name = expect_identifier();
 724
 725         if(check("["))
 726         {
 727                 var->array = true;
 728                 if(!check("]"))
 729                 {
 730                         var->array_size = parse_expression();
 731                         tokenizer.expect("]");
 732                 }
 733         }
 734
 735         if(check("="))
 736                 var->init_expression = parse_expression();
 737
 738         tokenizer.expect(";");
 739         return var;
 740 }
 741
 742 RefPtr<VariableDeclaration> Parser::parse_variable_declaration_with_layout()
 743 {
 744         RefPtr<Layout> layout;
 745         if(tokenizer.peek_token()=="layout")
 746                 layout = parse_layout();
 747
 748         RefPtr<VariableDeclaration> var = parse_variable_declaration();
 749         var->layout = layout;
 750
 751         return var;
 752 }
 753
 754 RefPtr<FunctionDeclaration> Parser::parse_function_declaration()
 755 {
 756         RefPtr<FunctionDeclaration> func = create_node<FunctionDeclaration>();
 757
 758         func->virtua = check("virtual");
 759         func->return_type = expect_type();
 760         func->name = expect_identifier();
 761         tokenizer.expect("(");
 762         while(tokenizer.peek_token()!=")")
 763         {
 764                 if(!func->parameters.empty())
 765                         tokenizer.expect(",");
 766
 767                 RefPtr<VariableDeclaration> var = create_node<VariableDeclaration>();
 768                 string token = tokenizer.peek_token();
 769                 if(token=="in" || token=="out" || token=="inout")
 770                         var->interface = tokenizer.parse_token();
 771                 var->type = expect_type();
 772                 var->name = expect_identifier();
 773                 func->parameters.push_back(var);
 774         }
 775         tokenizer.expect(")");
 776
 777         func->overrd = check("override");
 778
 779         string token = tokenizer.peek_token();
 780         if(token=="{")
 781         {
 782                 func->definition = func.get();
 783                 parse_block(func->body, true, &Parser::parse_statement);
 784         }
 785         else if(token==";")
 786                 tokenizer.parse_token();
 787         else
 788                 throw parse_error(tokenizer.get_location(), token, "'{' or ';'");
 789
 790         return func;
 791 }
 792
 793 RefPtr<InterfaceBlock> Parser::parse_interface_block()
 794 {
 795         RefPtr<InterfaceBlock> iface = create_node<InterfaceBlock>();
 796
 797         iface->interface = tokenizer.parse_token();
 798         if(!is_interface_qualifier(iface->interface))
 799                 throw parse_error(tokenizer.get_location(), iface->interface, "an interface qualifier");
 800
 801         iface->block_name = expect_identifier();
 802         iface->members = new Block;
 803         parse_block(*iface->members, true, &Parser::parse_variable_declaration_with_layout);
 804         if(!check(";"))
 805         {
 806                 iface->instance_name = expect_identifier();
 807                 if(check("["))
 808                 {
 809                         iface->array = true;
 810                         tokenizer.expect("]");
 811                 }
 812                 tokenizer.expect(";");
 813         }
 814
 815         return iface;
 816 }
 817
 818 RefPtr<Conditional> Parser::parse_conditional()
 819 {
 820         tokenizer.expect("if");
 821         RefPtr<Conditional> cond = create_node<Conditional>();
 822         tokenizer.expect("(");
 823         cond->condition = parse_expression();
 824         tokenizer.expect(")");
 825
 826         parse_block(cond->body, false, &Parser::parse_statement);
 827
 828         string token = tokenizer.peek_token();
 829         if(token=="else")
 830         {
 831                 tokenizer.parse_token();
 832                 parse_block(cond->else_body, false, &Parser::parse_statement);
 833         }
 834
 835         return cond;
 836 }
 837
 838 RefPtr<Iteration> Parser::parse_for()
 839 {
 840         tokenizer.expect("for");
 841         RefPtr<Iteration> loop = create_node<Iteration>();
 842         tokenizer.expect("(");
 843         string token = tokenizer.peek_token();
 844         if(is_type(token))
 845                 loop->init_statement = parse_statement();
 846         else
 847         {
 848                 if(token!=";")
 849                 {
 850                         RefPtr<ExpressionStatement> expr = create_node<ExpressionStatement>();
 851                         expr->expression = parse_expression();
 852                         loop->init_statement = expr;
 853                 }
 854                 tokenizer.expect(";");
 855         }
 856         if(tokenizer.peek_token()!=";")
 857                 loop->condition = parse_expression();
 858         tokenizer.expect(";");
 859         if(tokenizer.peek_token()!=")")
 860                 loop->loop_expression = parse_expression();
 861         tokenizer.expect(")");
 862
 863         parse_block(loop->body, false, &Parser::parse_statement);
 864
 865         return loop;
 866 }
 867
 868 RefPtr<Iteration> Parser::parse_while()
 869 {
 870         tokenizer.expect("while");
 871         RefPtr<Iteration> loop = create_node<Iteration>();
 872         tokenizer.expect("(");
 873         loop->condition = parse_expression();
 874         tokenizer.expect(")");
 875
 876         parse_block(loop->body, false, &Parser::parse_statement);
 877
 878         return loop;
 879 }
 880
 881 RefPtr<Passthrough> Parser::parse_passthrough()
 882 {
 883         tokenizer.expect("passthrough");
 884         RefPtr<Passthrough> pass = create_node<Passthrough>();
 885         if(cur_stage->type==Stage::GEOMETRY)
 886         {
 887                 tokenizer.expect("[");
 888                 pass->subscript = parse_expression();
 889                 tokenizer.expect("]");
 890         }
 891         tokenizer.expect(";");
 892         return pass;
 893 }
 894
 895 RefPtr<Return> Parser::parse_return()
 896 {
 897         tokenizer.expect("return");
 898         RefPtr<Return> ret = create_node<Return>();
 899         if(tokenizer.peek_token()!=";")
 900                 ret->expression = parse_expression();
 901         tokenizer.expect(";");
 902         return ret;
 903 }
 904
 905 } // namespace SL
 906 } // namespace GL
 907 } // namespace Msp